Strip tensioning apparatus



Dec. 23, 1952 ABBOTT 2,622,844

STRIP TEN-SIGNING APPARATUS Filed July 16. 1947 2 SHEETS-SHEET 1 Dec. 23, 1952 ABBQ'TT 2,622,844

STRIP TENSIONING APPARATUS Filed July 16, 1947 2 Sl-lEETSSl-IEET 2 Arr S Patented Dec. 23, 1952 2,622,844 STRIP TEN SIGNING APPARATUS Geofirey Joseph Abbott, Carshalton, England, as-

signor to Packers Supply Company Limited, New Malden, England, a company of Great Britain Application July 16, 1947, Serial No. 761,362 In Great Britain October 21, 1943 Section 1, Public Law 690, August 8, 1946 Patent expires October 21, 1963 2 Claims.

This invention, which is an improvement in or modification of the invention forming the subject of Patent No. 2,229,786, relates to apparatus for tensioning strip material such as binding strapping or wire of round or elliptical cross section, around boxes, bales, crates and other bodies, in preparation for joining together the ends of the strip material. The said apparatus includes a support, such as a body frame adapted to stand on the box or other package required to be bound, a pair of strip-gripping members mounted on the support in such a manner that they are capable of limited movement relatively to one another between gripping relationship and slipping relationship and that the first of said gripping members can be moved by and with the second relatively to the support, said gripping members being adapted, when said second of them is moved by an actuating member in one direction, first to co-operate with one another to grip and move the strip and thereafter to move apart to release their grip upon the strip.

An object of this invention is to provide such apparatus with simple and convenient means for keeping the strip, when desired, properly placed between the gripping members.

Another object is to provide gripping members of improved design and improved means for controlling and limiting their movement.

According to the present invention a strip-retaining member carried by, for instance pivotally mounted on, either of said gripping members is displaceable between a first position in which it overlaps the other of said gripping members in such a manner as to prevent the strip from moving transversely of its length from between the gripping members, and a second position in which it permits the strip to be inserted transversely of its length between the gripping members, said stripretaining member being biased, for example by gravity, towards said first position. The first gripping member may be of an angle section and said second gripping member pivotally mounted on said first gripping member for rocking about an axis normal to one limb of the angle so as to grip the strip against the other limb of the angle, the width of said other limb being equal to the width of the strip, and said strip-retaining mem her being pivotally mounted on said second gripping member. The second gripping member may have a convex gripping surface, the strip-retaining member having a surface which, when in one limit of its range of displacement, forms a lateral extension of the convex gripping surface.

According to a further feature of this invention the first gripping member is constituted by a yoke the limbs of which straddle a fixed lug supporting a bearing pin on the ends of which said limbs are mounted, the body of the yoke being bored and providing a bearing for a shaft to one end of which said second gripping member is fixed and to the other end of which a hand lever is fixed.

According to another feature a plug is adjustably fitted in one of said gripping members and is provided with a serrated end forming a gripping surface.

An embodiment of the invention as applied to a combined tensioner and jointing tool for fiat metal strapping will be described by way of example with reference to the accompanying drawings, in which:

Fig. 1 is a front elevation of the tool in use, the jointing mechanism being cut away,

Fig. 2 is a plan of the left-hand part of the tool as seen in Fig. 1,

Fig. 3 is a rear elevation of the tool,

Fig. 4 is a section of a detail taken on the line 44 in Fig. 2,

Fig. 5 is a section, taken on the curve 5-5 in Fig. 1,

Fig. 6 is a section, similar to Fig. 5, except that it shows the strapping in course of being inserted between the gripping members, and

Figs. 7 and 8 are front elevations of the tensioning mechanism in two difi'erent positions.

Referring to the drawings, the body of the tool, which may be a steel casting, includes a base plate I!) in which is fitted the lower die ll of the jointing mechanism. The remainder of the jointing mechanism, which may be of any desired kind, is accommodated in a housing integral with the base and standing in the middle thereof at the part cut away in Figs. 1 and 3.

On the ends of the base plate Ill are pairs of upstanding lugs [2A, 123 and BA, BB, through which extend shafts l4 and 15. On the front ends of these shafts are integral pawls I6 and H respectively and to the rear ends are fixed handles I8 and I 9 respectively, whereby the shafts can be rocked in the bearing lugs. The pawls I6 and I! are so shaped that a part ISA and HA of their noses is eccentric with respect to the shafts I4 and I5 and is provided with serrations adapted to engage the upper surface of strapping lying across the base plate when the handles I8 and I9 are in the positions shown. Tension springs 20 and 2| are provided between pins on these handles'and anchorages on the base and serve to hold the levers alternatively in the positions shown, 'or displaced away from each other in positions such that the pawl noses are raised clear of the base plate to permit the strapping to be inserted from the front between the pawls and the base plate. The extent to which the pawls can be moved away from the base plate is limited by engagement of lugs 22 and 23 on the levers l8 and H) with fixed stop pins 24 and 25. The pawls are provided with radially projecting flanges IBB and HB which engage in grooves 26 and 21 in the base whenthe pawls are in their operative position, in order to prevent the strapping from slipping towards the front of the machine.

In use the tool is placed upon .thebox 28 (Fig. 1) or other package to be bound and the levers |8 and I9 are operated to bring the pawls l6 and I1 into their open positions. (In Fig. 1 the tool is seen from the side which the operator conveniently occupies; and the terms front," back, right-hand and left-hand will be hereinafter used to refer to the tool as seen in Fig. 1.) Thereupon the free end 29A of the strapping is inserted between the base it! and the pawls and the lever I8 is moved to cause the left-hand pawl It to grip the inserted end of the strapping which is looped around the box. The portion of strapping 29B returned over the top of the box is inserted between the base |EI and the right-hand pawl over the previously inserted free end of the strapping, under a fixed guide peg 50 having a bevelled end, and through the tensioning means at the left-hand end of the machine, the upper part of the pawl l3 being stepped at ISO to provide a straight path for the strapping between the pawl l1 and the tensioning means. The front of the step is bevelled at IBD.

The tensioning means, which serve to pull the portion 293 of the strapping to the left, soaS to tension the loop of strapping around the box, will now be described.

A lug 30 on the frame of the machine carries a fixed bearing pin 3| lying parallel to, above or somewhat to the left of the pawl shaft I4. On this pin is journalled a yoke 32, which embodies the first gripping member and the limbs of which straddle the lug 33. The front portion of the yoke is provided with a downward extension 33 carrying a forwardly projecting grippin lug 33, the upper surface 34A of which lies between the vertical planes containing the edges of the strapping in position in the tool. This gripping member is thus Of angle section, as is seen in Fig. 5, the front of the vertical limb 33 of the angle serving as a locating face for the strapping 29B in position in the tensioning mechanism and the horizontal limb forming the gripping member. The surface 34A is slightly convex in the longitudinal direction. A screw plug 35 (Fig. 4) is fitted in a tapped bore passing through the gripping lug 34, the upper end of the plug 35 being provided with hardened serrations which project above the surface 34A of the lug. The plug 35 is held by a locking screw 33.

The body of the yoke 32 is bored to serve as a bearing for a shaft 31 to the back end of which is fixed a hand lever 38. To the front end of the shaft 31 is fixed the second gripping member formed by a gripping arm 39 having a smooth convex lower surface 393 which lies between the vertical planes containing the edges of the strapping in position in the tool and which extends substantially further to the right than the surface'34A of the gripping lug 34. The arm 39 32011 angle sec.tion..(Figs. 5. and 6), the vertical 4 limb 39A of the angle upstanding at the front face of the arm. A pin 43 fixed in the yoke 32 co-operates with the horizontal limb of the anglesection arm 39 to limit displacement of the arm in the direction away from the surface 34A of the gripping lug.

A fiat strapping-retaining blade 4| is mounted on the front of the gripping arm 39, being carried by a pivot screw 42 fixed in the right-hand end of the vertical limb 39A. A screw 43, also fixed in the limb 39A, passes through an arcuate slot 44 in the blade 4| so as to limit its movement about the pivot screw 42 between the working position (Fig. 5) which it normally occupies and a raised position (Fig. 6) in which its lower edge forms a forward extension of the convex lower surface 39B of the gripping arm.

The hand lever 38 is arranged to engage two abutment pins 45 and 45 (Fig. 3) fixed in the back of the body of the tool, the pin 45 being near to the fixed bearing pin 3 The handle end of the lever 33 is heavy enough to maintain this lever, acting on the pin 35 as a fulcrum, in the position shown in Figs. 1 and 3, in which the yoke 32 is raised to the limit in the clockwise sense (as seen from the front) of its range of movement, and the gripping surfaces 34A and 33B are spaced apart.

In operation, the part 29B of the strapping is passed rearwards, in the manner hereinbefore described under the pawl ll and the peg 50, and over the beveled front edge |6D of the pawl |3 until it engages the front of the gripping lug 34. The strapping is then raised to lift the pivoted blade 4| to the upper limit of its range of movement, whereupon the blade 4| serves as a guide for rearward movement of the strapping between the gripping surfaces, as shown in Fig. 6. When the strapping is fully inserted between these surfaces, with its back edge against the downward extension 33 of the yoke 32, the blade 4| is moved by gravity to the position shown in Fig. 5, retaining the strapping in position between the gripping surfaces. The lever I3 is now raised to bring the right-hand pawl into gripping engagement with the strapping.

The hand lever 38 is moved counter-clockwise (as seen from the front). At first it pivots on the abutment pin 45, allowing the yoke 32 to rock by gravity counterclockwise about the bearing pin 3|. During this initial movement the gripping lug 34 moves counter-clockwise about the axis of the shaft 31 relatively to the gripping arm 39, so that the strapping'is lightly engaged between the gripping surfaces. On continued counter-clockwise movement of the hand lever 38, the yoke 32 continues to move by gravity counter-clockwise about its bearing pin 3|, until the right-hand end of the gripping lug 34 engages the fixed lug |2A, and after a further slight movement of the hand lever 38 the gripping arm 33 engages the pin 43 in the yoke. The hand lever is now in the counter-clockwise limit of its range of movement asshown in Fig. 7

During an initial part of the clockwise return stroke of the hand lever 38, the shaft 3'! is rotated clockwise in the stationary yoke 32, until the gripping arm 39 nips the strapping against the serrated upper end of the plug 35 in the gripping lug 34. The parts are now in the position shown in Fig. 8. On continued clockwise movement of the hand lever 38, this lever and the yoke move in unison about the bearing pin 3| drawingv the strapping 29B to the left. As the tension in the strapping increases, the torque applied to the shaft by the hand lever likewise has to be increased, and with it the gripping pressure applied to the strapping by the parts 34; and 39, so that there is no risk of the strappings slipping in the tensioning mecha nism. The curvature of the under surface 39B of the gripping arm is such that the length of strapping between the pawl Ill and the gripping arm 39 is substantially tangential to the surface 393 throughout the tensioning stroke.

If new the movement of the hand lever 38 is reversed before it reaches the abutment pin the grip of parts 3-; and 39 on the strapping is released, so that these parts can slide freely to the right along the strapping, return movement of which is prevented by the right-hand pawl ll.

If, on the other hand, the hand lever 38 is moved clockwise so far that it re-engages the abutment pin 45, further movement of the hand lever in the same direction has the effect of rocking the yoke 32 clockwise with respect to the gripping arm 39, so that the gripping surfaces are disengaged from the strapping. This action, in co-operation with the curvature of the gripping surface 393, ensures that the part of the strapping passed through the tensioning mechanism is only slightly bent to a smooth curve, and the resulting absence of kinks and of substantial permanent set renders this part of the strapping suitable for use in a subsequent binding operation.

lhe strapping having been tensioned to the desired extent about the box, the portions 0t strapping between the pawls are united and the part of the strapping between the joint and the tensioning mechanism is severed by the action of the jointing mechanism. The severed end of the unused portion of strapping is finally drawn to the left through and clear of the tensioning mechanism.

I claim:

1. Apparatus for tensioning strip material around boxes, bales, crates and other bodies, comprising a support, a pair of strip-gripping members mounted on said support so as to be capable of limited movement relative to one another between gripping relationship and slipping relationship and one of said gripping members being movable by and with the other of said gripping members relative to the support, an actuating member for imparting movement to said other gripping member, an elongated displaceable strip-retaining member, pivotally mounted at one end upon one of the said gripping members and having pin and slot connection at its other end with the same said ripping member and displaceable thereon about said pivot at one end and to an extent limited by said pin and slot connection at the other end between two positions in one of which it overlaps the other gripping member in such a manner as to prevent a strip from moving transversely of its length between the said gripping members and in the other of which it permits the strip to be inserted transversely of its length between the gripping members, said displaceable strip-retaining mem her being biased towards said overlapping position by gravity.

Apparatus for tensioning strip material around boxes, bales, crates and other bodies, comprising a support, a pair of strip-gripping and slipping members mounted on said support so as to be capable of limited movement relative to one another between gripping relationship and slipping relationship and one of said gripping members being movable by and with the other of said gripping members relative to the support, an actuating member for imparting movement to said other gripping member, means whereby movement of said actuating member in one direction first moves said gripping members into a co-operative relationship so as to grip and move the strip located between them and thereafter moves them apart so as to release their grip upon the strip, a displaceable strip-retaining member carried by one of said gripping members and displaceable thereon betwen two positions, in one of which it overlaps the other gripping member in such a manner as to prevent a strip from moving transversely of its length from between said gripping members, and in the other of which it permits the strip to be inserted transversely of its length between the gripping members, said strip-retaining member being biased towards the first of said positions, and means to limit the movement of said displaceable strip-retaining member under said bias so that said displaceable strip-retaining member may be moved from the said first to the said other position against said bias, transversely of the general direction taken by the strip material when between the strip-gripping members, by the engagement of the strip material with the edge of said displaceable strip-retaining member as the strip material is inserted between the strip-gripping members.

GEOFFREY JOSEPH ABBOTT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 812,808 Bowers Feb. 20, 1906 1,069,935 Filliez Aug. 12, 1913 1,517,903 Guenther Dec. 2, 1924 2,072,566 Perrelet Mar. 2, 1937 2,229,786 Abbott Jan. 28, 1941 2,375,769 Childress et a1. May 15, 1945 FOREIGN PATENTS Number Country Date 28,239 Great Britain Dec. 23, 1907 387,139 Great Britain Feb. 3, 1933 428,181 Great Britain May 8, 1935 

